1. Field of the Invention
This invention relates to a camera arranged to be capable of detecting abnormalities of the shutter.
2. Description of the Related Art
Some of the known electrically-controlled type shutter devices for cameras are arranged to electrically detect an abnormal shutter action and to give a warning.
For example, a camera disclosed in Japanese Utility Model Application Laid-Open No. SHO 57-722 is arranged to detect, by first switch means, whether or not the shutter is closed; to detect, by second switch means, whether or not the shutter is fully open; to determine, by a decision circuit, whether the shutter blades are in correct positions before and after the generation of a shutter control signal; and to give a warning if the shutter is determined to be malfunctioning.
According to the above-stated arrangement of the prior art, however, it has been impossible to confirm the accuracy of the shutter action, though the shutter action is detectable. Further, since the movement of shutter blades is detected by a mechanical switch according to the prior art arrangement, the bouncing or chattering of the detection switch prevents accurate detection of the travel of the shutter. Therefore, a warning might be given even when the shutter action is normally performed.